The website will meet increasing public demand for weather information, especially from hikers, according to Wong Ming-chung, the Observatory's assistant director.

'As PDAs are popular among the public, we feel there's a need to provide these users with the most updated weather information, especially in rapidly changing weather situations.'

Dr Wong said the observatory planned to start the service before the start of this year's rainy season. The service would be particularly useful to hikers, allowing them to use the latest weather information to plan their activities, he said.

Frequent hiker Yip Ching, member of the Kin Hang Hiking Club, said he did not find the website useful, even though he has a PDA.

'Hikers usually check the weather before they go. If the weather's bad, we won't go at all,' he said.

Mr Yip said he took his PDA with him every time he went hiking, but it did not have internet access. He said he preferred getting weather information from the radio.

The website includes updated weather warnings, weather reports and forecasts. Weather information in various world cities is also included. The public can view the latest satellite and radar images of Hong Kong, along with weather charts, rainfall maps and regional weather information. Regional weather information will be updated on average every five minutes, while images from radar and satellite sources will be updated every 10 to 60 minutes.

The Observatory spent three months setting up the website at a cost of $50,000. The website address is http://pda.hko.gov.hk.